What is the meaning of the numbers associated with each key phrase?
When you run the sample program “test_api.exe” (or “test_api.bin” for Unix platforms), each key phrase will be output with a number after it. These numbers are the scores returned by the API function ExtrGetScoreByIndex(). The score of a phrase is an estimate of its value as a key phrase. key phrases are ranked in order of descending score. A score can be any positive real number. The scores with long documents as input tend to be higher than the scores with short documents. The method of calculating the score is described in detail in Learning to Extract key phrases from Text. For some applications, it might be desirable to normalize the score.
